My son played a lot of sports before high school when he narrowed it down to baseball, soccer, rec basketball and travel baseball in the summer.
As a preteen he played travel soccer, rec basketball, travel basketball, rec baseball and travel baseball. In middle school he played football, travel soccer, basketball, rec basketball, travel basketball, baseball and travel baseball.
Then add in all the pickup games he played in various sports.
A top sports ortho specialist told me he should be fine since he's playing various sports and not working his joints and muscles the same way all the time. The specialist (a friend of the family) x-rayed his growth plates annually through age twelve.
As a senior in high school my son fell on his shoulder requiring shoulder separation surgery. He was fortunate to have a surgeon who also operated on pro athletes. The surgeon said there was a lot of wear and tear in the shoulder that didn't look like it was from pitching. My son was mostly a relief pitcher and never overused.
My son is a very physical athlete. He pushed the limit on contact in soccer. He banged for rebounds and scrambled for loose balls in basketball. He caught in baseball until he was twelve. Then there were all the balls he dove for at short and in center in middle school and high school.
I'm not suggesting kids play less. I would let my son do it all over again the same way. But I might be a little more concerned about the wear and tear in middle school from all the activity.
After surgery and rehab he threw harder as the surgeon suggested he might from having his shoulder tightened up. But I would never suggest going through surgery and rehab as a way for a kid to up his game. Besides, he missed senior year of soccer when the team went the furthest in states.